The present invention refers to a position sensor, particularly a sensor applicable to a linear compressor, for detecting the position of the piston, as well as to a compressor provided with a position sensor of its piston.
1. Field of the Invention
2. Description of Related Art
A linear compressor basically comprises a piston that can be axially displaced in a hollowed body, such piston compressing the gas used in the refrigeration cycle. Suction and discharge valves close to the end of the stroke of the piston regulate gas inlet and outlet in the cylinder or hollowed body. The piston is driven by an actuator that supports a magnetic component, which is driven by a linear motor. The piston is connected to a resonant spring and, together with the magnetic component and the spring, forms the resonant assembly of the compressor.
The resonant assembly, driven by the linear motor, has the function of developing a linear alternative movement, causing the movement of the piston inside the cylinder to perform an action of compressing the gas admitted by the suction valve as far as the point at which it can be discharged to the high-pressure side through the discharge valve.
Variations in the conditions of operation of the compressor, or variations in the feed voltage may cause the resonant assembly to displace beyond an acceptable limit, leading the top of the piston to knock against the head, thus causing noise and even damages to the compressor.
There are various solutions for controlling the movement of the piston so as to avoid collision of the piston with the head. One of them is to control the voltage level applied to the motor, so as to prevent the piston from advancing beyond the predetermined point and colliding with the head.
Other solutions detect the excess advance of the piston at the time of its collision with the head, thus not preventing damages to the compressor.
In order to avoid the above-cited problems, some solutions propose the use of position sensors, usually inductive transducers designed to detect the passage of the piston from a point close to the end of its stroke and to prevent it from knocking against the head. The problem of using these sensors lies in the fact that such devices are expensive and difficult to install, which raises the production costs of the compressor.
The objective of the present invention is to provide a sensor capable of detecting the position of the piston, which prevent collision of the latter with the head altogether, is easy to construct and to install, thus reducing the production and manufacture costs of the compressor.
This objective is achieved by means of a sensor, particularly one that can be employed for detecting the position of a piston, the piston being axially displaceable in a hollowed body, the compressor comprising a valve blade, this blade being positioned between a head and the hollowed body, the sensor comprising a probe electrically connected to a control circuit, the probe being capable of detecting the passage of the piston at a point of the hollowed body and signaling this to the control circuit.
Another objective of the present invention is to provide a compressor having a sensor that is capable of detecting the passage of its piston at a point and signaling this to a circuit, with a view to prevent it from knocking against the head.
This objective is achieved by means of a compressor, particularly a linear one comprising a piston that is axially displaceable inside a hollowed body, the compressor comprising a valve blade, this blade being positioned between a head and the hollowed body, the compressor comprising a probe electrically connectable to a control circuit, the probe being capable of detecting the passage of the piston at a point of the hollowed body and signaling this to the control circuit.